Effect of hybrid basalt fibre length and content on properties of cementitious composites

Nowadays, basalt fibre is gaining popularity in the field of construction materials due to its low production cost and enhanced mechanical properties. However, research is still needed into the use of a single type of fibre with different lengths in composite materials. Therefore, in this paper the hybridisation of basalt fibre of various lengths and contents is studied in order to take full advantage of multi-scale characteristic(s) with a single type of fibre, while the fundamental mechanical properties of single-length basalt-fibre-reinforced cementitious composites and hybridisation of different-length basalt-fibre-reinforced composites are investigated. Additionally, a hybrid fibre coefficient is developed to evaluate the effect of hybrid fibre in cementitious materials. A total of 17 mix proportions were made containing either a single length or a combination of four different lengths of basalt fibre (3, 6, 12 and 20 mm) with various total volume contents. The paper shows that the hybridisation of four different lengths of fibres in cementitious composites generally improved mechanical properties in comparison to plain and single-length fibre-reinforced mortar. The hybrid fibre coefficient also showed good consistency with the results of mechanical properties. Scanning electron microscopy demonstrated the proper bonding of basalt fibre with cementitious composites.